Field of the Invention
The present invention relates to a composition, a method for producing a film with the composition, and a method for producing a liquid discharge head.
Description of the Related Art
In recent years, techniques for further enhancing recording characteristics of inkjet recording systems have been developed. An inkjet recording head discharges small droplets through openings of discharge ports to a recording medium represented by a paper sheet to thereby record an image. The performance of inkjet recording heads has been improved by employing smaller droplets, a higher driving frequency, and a larger number of discharge ports. In order to discharge such small droplets with stability and maintain the discharge performance, it is important that the surface having openings of discharge ports is always maintained in the same state. In order to maintain the state of the surface having openings of discharge ports, a surface treatment of forming a water-repellent layer is often carried out on a channel-forming member having openings of discharge ports. In addition, in order to maintain the state of the surface having openings of discharge ports, ink remaining on the surface having openings of discharge ports is regularly removed by wiping with a rubber blade or the like.
The water-repellent layer is desirably not eroded by liquid such as ink and remains adhered to the channel-forming member, even after being wiped (rubbed) with a blade or the like. Various inks are used for inkjet recording heads and examples thereof include alkaline inks, acidic inks, and inks containing organic solvents. The water-repellent layer desirably has durability against such various inks and is capable of adhering to the channel-forming member. In addition, there has been a demand for simultaneous formation of the channel-forming member and the water-repellent layer from the standpoint of simplification of production processes and reduction in the production cost. In other words, there has been a demand for a channel-forming member that itself has water repellency. However, since fluorine-containing compounds having water repellency generally have a low solubility in other resins, it is difficult to use such compounds as mixtures in combination with photosensitive resins.
The following is a disclosed example of a material that is used for a surface treatment providing a water-repellent and ink-repellent film having durability and can be applied to channel-forming members. Japanese Patent No. 4174124 discloses a water-repellent antifouling coating composition that includes a fluorine-containing epoxy resin having in a single molecule one or more perfluoroalkyl groups having 6 to 12 carbon atoms and two or more alicyclic epoxy groups, and a cationic polymerization catalyst.
Other compounds that have, instead of perfluoroalkyl groups, perfluoro oxy alkylene groups that have a low surface free energy, water repellency, releasability, an antifouling property, and the like, that is, perfluoropolyether groups (hereafter sometimes referred to as PFPE groups) have been attracting attention. Japanese Patent Laid-Open No. 2011-184517 discloses a water-repellent antifouling coating composition that includes a fluorine-containing epoxy resin synthesized by a polymerization reaction between an acrylic monomer having a PFPE group having 4 to 8 carbon atoms and an acrylic monomer having an epoxy group in which the composition proportion of the latter monomer is lower than that of the former monomer.